NEW YORK, Feb 10: President Pervez Musharraf said on Monday that he had suspected for at least three years that Pakistan's top nuclear scientist was sharing nuclear technology with other countries , but argued that the United States had not given him convincing proof.

In an interview with the New York Times, President Musharraf shared blame for the delay with Washington, saying it was not until October that American officials provided evidence of the activities of the scientist, Dr Abdul Qadeer Khan.

"If they knew it earlier, they should have told us," President Musharraf said. "Maybe a lot of things would not have happened." In Washington on Monday, a senior Bush administration official told the Times that General Musharraf was not given highly specific information about Dr Khan's activities until last autumn. But the official noted that the United States conveyed more general warnings about Dr Khan's activities starting in 2001.

At the same time, General Musharraf told the paper he had seen signs that Dr Khan was sharing nuclear technology, including "illegal contacts, maybe suspicions of contacts," and "suspicious movement" connected to Dr Khan's laboratory. But he said he was concerned that investigating Dr Khan, a national hero for his role in developing its nuclear weapons, could provoke a political backlash.

President Musharraf said he forced Dr Khan to retire from his post as head of a nuclear weapons lab in March 2001, to prevent him from transferring any more nuclear secrets. That is the first time the general has cited Dr Khan's nuclear activities as the reason for his departure.

"We nipped the proliferation in the bud, we stopped the proliferation," he said of Dr Khan's removal. "That is the important part." "It was extremely sensitive," he said. "One couldn't outright start investigating as if he's any common criminal."

He informed the paper that the brigadier in charge of security for Dr Khan's top-secret laboratory never reported anything. "He didn't, and frankly, he hasn't even now," the president said. "He in fact has said that yes, he regrets that he was inefficient, he couldn't unearth, he didn't know. He says he didn't know whatever was going on. And he swears by that even now."

President Musharraf emphatically denied reports by American intelligence officials that Dr Khan had struck a barter agreement with North Korea in which Pakistani nuclear technology was exchanged for North Korean ballistic missile technology.

He said Pakistani cargo planes spotted in North Korea in July 2002 were picking up surface-to-air missiles Pakistan had purchased at the height of tensions with India, the paper said. However, he told the paper that the government was "still looking into the details" about what, beyond designs, had been transferred to North Korea.

He said that despite his suspicions, he had no idea how extensive Dr Khan's network was, nor how long it had been operating. "We didn't know that this is so deep that it started somewhere in the late 80's," he said. "We didn't know that at all. And frankly again, the sensitivity of the issue we tapped it and we just sidelined this one individual."

The paper added that on Wednesday, President Bush is expected to give what one senior official at the White House described on Monday evening as a "lengthy, detailed speech on what must change in the area of stopping proliferation."